If a multinodular goiter grows large or presses against nearby structures, a person may notice the following symptoms:. A person with a toxic multinodular goiter may have symptoms of hyperthyroidism.
These include, but are not limited to:. One cause of multinodular goiter is an iodine deficiency, although this is rare in the United States. The thyroid uses iodine to produce its hormones.
Without enough iodine, the thyroid cannot perform its normal functions. For this reason, food manufacturers often add iodine to salt, called iodized salt, to reduce the prevalence of thyroid dysfunction. Some people have greater risk factors for developing a multinodular goiter. Risk factors include:. If the thyroid gland is not making enough thyroid hormone, the pituitary gland in the brain will release more of the thyroid-stimulating hormone TSH.
The excess TSH can cause the thyroid to enlarge and create a multinodular goiter. Likewise, an overactive thyroid that is making too much thyroid hormone can cause the thyroid to enlarge and become multinodular. Blood tests can help to diagnose thyroid problems, especially tests for thyroid-stimulating hormone TSH. If TSH levels are high, a person may have hypothyroidism low thyroid hormone levels because the body is trying to ramp up thyroid hormone production.
Follow up thyroid hormone tests to check for levels of hormones called T3 and T4 may be required to understand the complete picture. A doctor may also perform thyroid imaging tests. These include a thyroid ultrasound. This test uses sound waves to recreate images of the thyroid, including the size and number of any nodules. Sometimes, a doctor may recommend taking a biopsy of the thyroid nodules to test for the presence of cancerous cells.
A common biopsy method uses a small needle guided by an ultrasound, known as fine needle aspiration FNA. Doctors will probably recommend that anyone who has a nodule larger than 1 centimeter cm in size has a biopsy. The hypothalamus signals the pituitary gland to make a hormone known as thyroid-stimulating hormone TSH.
The pituitary gland — located below the hypothalamus — releases a certain amount of TSH , depending on how much T-4 and T-3 are in the blood. The thyroid gland, in turn, regulates its production of hormones based on the amount of TSH it receives from the pituitary gland. Enlargement of the thyroid can expand the gland well beyond its typical size and cause a noticeable bulge in the neck.
This can be caused by single or multiple nodules lumps in the thyroid or by an autoimmune process. Anyone can develop a goiter. It may be present at birth or occur at any time throughout life. Some common risk factors for goiters include:. A goiter itself usually doesn't cause complications. The appearance may be troublesome or embarrassing for some people.
A large goiter may obstruct the airway and voice box. Changes in the production of thyroid hormones that may be associated with goiters have the potential for causing complications in multiple body systems.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Overview Enlarged thyroid Open pop-up dialog box Close. Enlarged thyroid Widespread enlargement of the thyroid can expand the gland well beyond its typical size left and cause a noticeable bulge in the neck right.
Request an Appointment at Mayo Clinic. Pituitary gland and hypothalamus Open pop-up dialog box Close. Pituitary gland and hypothalamus The pituitary gland and the hypothalamus are located within the brain and control hormone production.
Thyroid nodules Open pop-up dialog box Close. Thyroid nodules Enlargement of the thyroid can expand the gland well beyond its typical size and cause a noticeable bulge in the neck. Share on: Facebook Twitter. Show references Goiter. In either case, if surgery is selected as the treatment, a surgeon with expertise in thyroid surgery should be chosen to minimize the risk of complications. Radioactive iodine can be used to cure the hyperthyroidism from a toxic nodule or toxic multinodular goiter.
For toxic multinodular goiter, the size of the thyroid is important. An enlarged toxic multinodular goiter may not be successfully treated with just one dose of radioactive iodine, and a second course of treatment may be required.
The remaining thyroid typically provides adequate amounts of thyroid hormone in most patients after radioactive iodine, but some patients may need to take a thyroid hormone pill following treatment. The nodules themselves often shrink but usually still remain, unlike after surgery.
Depending on how much the nodule shrinks, it may require continued surveillance and monitoring after the iodine treatment, and ultimately may need to be removed for other reasons, such as a concerning biopsy or large size that causes neck pressure. It is important to remember that other nodules in your thyroid that are not toxic may influence which treatment option is best.
Fine needle aspiration biopsy may be necessary for some of these nodules. For information on thyroid patient support organizations, please visit the Patient Support Links section on the ATA website at www. Toxic Nodule and Toxic Multinodular Goiter.
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